A cyclone dust collector is an apparatus that collects and removes fine liquid or solid particles in gas stream. The dust collector uses a principle that, if dust laden gas is applied with acceleration much larger than gravity, a separating velocity of dust particles from gas becomes larger compared to a settling velocity by weight. A structure of conventional cyclone dust collector is shown in FIG. 1. The conventional apparatus provides a structure with: a main body (100) integrated vertically with a storage tank (130) installed at its bottom; a gas inlet (110) formed at one side horizontally along a tangential direction from an outer wall at an upper part of the main body to communicate with the inside of the main body; and an outlet (120) inserted into the upper part of the main body from the top side of the main body to exhaust gas.
The dust collector was initially used to remove dust particles contained in a flue gas of the boiler. Now, the dust collector is used to treat exhaust gases in many industrial fields such as chemical factories, waste incinerators, etc.
Existing methods for removing dust particles from exhaust gas are classified into a mechanical type of gravitation, filtration, inertial impaction, centrifugal devices and scrubber, and an electrical type of applying electric field to dust particles suspended in gas and collecting particles by electrostatic forces. The mechanical type includes wet and dry dust particle collecting methods. The wet method has a high dust collecting efficiency but produces excessive amounts of waste water. Therefore, dry method dust collectors using bag filters or cyclones are mainly used. Further, the electrostatic precipitator having a very high dust collecting efficiency is widely used. The electrostatic precipitator has an excellent merit in dust collecting efficiency as high as 98%. However, the electrostatic precipitator has a limitation in workable temperature of exhaust gas and a demerit of expensive facilities cost. The dust collector using bag filter has 98% dust collecting efficiency but has a problem of limited workable temperature. The cyclone dust collector has a dust collecting efficiency relatively low compared to the other dust collector. Further, when used solely, a pressure loss as much as 50-150 mmAq is relatively low compared to the bag filter apparatus. However, when applied as primary dust collector in front of an electrostatic precipitator collector or bag filters, the whole pressure loss becomes very high and increases the operation cost. Further, if the conventional cyclone is applied to remove abrasive dust particles, the cyclone is easily worn out and its lifespan is decreased. In this case, an inner wall of the cyclone dust collector has to be reinforced with anti-abrasive material causing increase of cost for facilities.